Base (minimal generating set) of the Sylow 2-subgroup of S₂n is called diagonal if every element of this set acts non-trivially only on one coordinate, and different elements act on different coordinates. The Sylow 2-subgroup ...

We consider the wreath product of two symmetric groups as a group of blocks permutations and we study its conjugacy classes. We give a polynomiality property for the structure coefficients of the center of the wreath product ...

Using (introduced by the first author) the method of (min, max)-equivalence, we classify all serial principal posets, i.e. the posets S satisfying the following conditions: (1) the quadratic Tits form qS(z) : Zˢ⁺¹ → Z of ...

Let H be a finite dimentional Hopf algebra over a field k and H∗ the dual Hopf algebra of H. Then a commutator right H∗ -Galois extension B of BH is characterized in terms of the smash product B#H and some relationships ...

For vertices u and v in a connected graph G = (V, E), the set ID[u, v] consists of all those vertices lying on a u−v longest path in G. Given a set S of vertices of G, the union of all sets ID[u, v] for u, v ∈ S, is denoted ...

For a commutative ring R and an ideal I of R, the ideal-based zero-divisor graph is the undirected graph ΓI(R) with vertices {x∈R−I:xy∈I for some y∈R−I}, where distinct vertices x and y are adjacent if and only if xy∈I. ...

We characterize the endomorphism monoids, End(G), of the generalized graphs G of order n with a minimum degree n − 3. Criteria for regularity, orthodoxy and complete regularity of those monoids based on the structure of G ...

We give an exact formula for the logarithm of the free spectra of band varieties.

In this note, it is proved that the generalized path algebras over standardly stratified algebras are also standardly stratified, and the generalized path algebras over quasi-hereditary algebras are also quasi-hereditary. ...

We compute the growth function of the generalized adding machine and show that its generating function is not algebraic.